In /usr/bib/cpuoverclock.py only pxa270 is implemented (which I guess id for C1000/3x00 models), therefor I guess that values for C860 are good for all pxa255 based models (750,760,860).
What about c700, its a pxa250 will pxa255 settings be good for pxa250 too ?
I've no idea what the 7500 has inside ;-)
Not sure what to do for 6000, 5600 and 5500 they are not supported by pdaxrom current.